传染病学课件 15、Shigellosis(细菌性痢疾)2015

Bacillarydysentery(shigellosis)

Departmentofinfectiousdisease

2ndAffiliatedHospitalCQMU

NINGLING

1Diarrheaclinicalcommonsymptom,canbecausedbyvariousdiseasesConcept:changesinstool,includingthefrequencyandcharacterNormalcondition:time:1-2timeadayvolume:about200~400gcolour:yellow,yellowishgreen,greenshape:shaped,withoutmucus、purulent、bloodClassfication

acute:within2moschronic:morethan2mos

2InfectiousdiarrheaConceptDiarrheacausedbyintestinalinfectionwithanykindofpathogen.Pathogensincludebacteria,viruses,parasites,andfungi,etc.Bacterialdiarrhea

Cholera:Aclassinfectiousdiseases

Bacillarydysentery,amebicdysentery,typhoidandparatyphoid:Bclassinfectiousdiseases

Bacterialdiarrhea:Cclassinfectiousdiseases

otherthantheabove3Shigellaspeciesareaerobic,non-motile,glucose-fermenting,non-spore-forming,gram-negativerods.

Itishighlycontagious,causingdiarrheaafteringestionofasafewas10

organisms.sensitivetoallkindsofchemicaldisinfectantsalldysenterybacillus

produceendotoxinpartofdysenterybacillusproduceexotoxin(shigatoxinshigatoxins)Etiology4etiologytwokindsofdysenterybacillusantigenOantigenandantigenofKAccordingtotheOantigen，dividedinto4groupsand47serotypeNameofbacteriaGroupSerumtypeandsubtype痢疾志贺菌(S.dysenteriae)

A

1-12福氏志贺菌(S.flexneri)

B

1a,b,c,2a,b,3a,b,c,4a,b,c,5a,6x鲍氏志贺菌(S.boydii)

C

1-18宋内志贺菌(S.sonnei)

D

15Etiology6

EpidemiologySource:patients，especiallyatypicalpatients,chronicpatientsandcarriersRouteoftransmission：digestivetracttransmissionSusceptiblepopulation：generallysusceptible

thehighestincidence：childrenthehighigherincidence：youngandmiddle-agedEpidemiologicalfeature：alltheyearround,hasobviousseasonal,mosthappensinsummerandfall7EpidemiologyTheincidenceindevelopingcountriesis20timesgreaterthanthatinindustrializedcountries.>95%ofshigellainfectionsareasymptomatichencetheactualincidencemaybe20timeshigherthanisreported.8ShigellosisinChina910

Pathogenesisdependson

thenumberofbacteria

pathogenicity

humanbodyresistance11

Pathogenesis

Bacterialinfectingspecies/serotypeVirulenceamountHostageImmunologicstatusnutritionalstatusofthehost.12细菌性胃肠道感染发病机制数量经口初始入侵的病原菌数量通过胃酸等胃肠道防御屏障后进入肠腔有效定植和繁殖的数量毒力侵袭力黏附因子：菌毛或非菌毛黏附素荚膜、微荚膜：干扰调理，抵抗吞噬侵袭性酶：协助病原菌扩散和抗吞噬微菌落（microcolony）细菌生物膜（biofilm）

毒力弱的机会性致病菌藉此引起医源性感染毒素外毒素（exotoxin）内毒素（endotoxin）细菌侵入胃肠道鞭毛：有助于细菌在胃肠道运动致病岛基因编码产物：如沙门菌Ⅲ型分泌系统（TTSS）13

Dysenterybacillus

stomachintestinesIntestinalmucosalepitheliumandlaminapropriabreeding,intestinalmucosainflammation,necrosisandulcersabdominalpain,diarrheaandpurulentbloodexotoxinwaterydiarrheaandnervoussystemsymptomsendotoxinfeverandbloodpoisoningsymptomsDICandthrombosisanaphylaxis

reactionvasoactivesubstanceacutemicrocirculationdisturbancesepticshockmultipleorganfailurePathogenesis14

pathologylesions：majorinsigmoidcolonandrectumacutestage：diffusefibrinexudativeinflammation，superficialmucosalulcer，intestinalperforationandmassiveintestinalbleedingseldomlycausedchronicstage：bowelwallthickened，polypoidhyperplasiaandscarformed，leadtobowelstenosistoxictype：lightchangesincolon,obvioussystemicsymptoms,mostofthevisceraofmicrovascularspasmandpermeabilityincreased15

mucosaledema

erythema

friability

superficialulcers

focalmucosalhemorrhageGrosspathology:PATHOLOGY16

epithelialcellnecrosis

gobletcelldepletion

polymorph&mononuclearcellinfiltratesinlaminapropria

cryptabscessformation.MicroscopicpathologyPATHOLOGY17BasicClinicalPresentations:(1)waterydiarrheaassociatedwithvomitingandmildtomoderatedehydration(2)dysenterycharacterizedbyasmallvolumeofbloody,mucoidstools,andabdominalpain(crampsandtenesmus)1819

Clinicalmanifestationsincubationperiod：average1-2days，fromhoursto7daysClinicalmanifestationsassociatedwithtypes:dysenteryshigellainfectionisheavierClinicalclassificationAcutebacillarydysentery

coventionaltype：typicalmildtype：atypicaltoxictype：shock,cerebral,andmixedtypeChronicbacillarydysentery

Acuteattacktypetype

Chronicdelayedtype

Chronicobscuretype

20

ClinicalmanifestationsAcutebacillarydysentery:coventionaltype,typicaltypeacuteonsetabdominalpain,diarrheaandtenesmus;chillsandfeverdefecatetime:10times/day,butquantityislittle.firstlyloose,quicklyturnintomucouspurulentblood,nofecalmassleftlowerabdomentendernessandbowelsoundslouderthecourseofaboutaweekorsoasmallnumberdevelopintochronicstage21

ClinicalmanifestationsAcutebacillarydysentery:mildtype,atypicaltypetoxemicsymptomsandtheintestinalsymptomsarelighter,without

feverorlowfeverdiarrheaseveraltimesperday,loosestoolshavemucuswithoutpurulentblood,mildabdominalpain,tenesmusisnotobvioussomedevelopintochronicstage22

ClinicalmanifestationsAcutebacillarydysentery:toxictypeclassficatedintoshock,cerebral,andmixedtypeofteninchildren,abruptlyonsetseveretoxemia:highfever(temperaturecanreachmorethan40℃),listlessness,drowsiness,comaandconvulsions,canrapidlycirculatoryandrespiratoryfailureinshockand(or)toxiccerebralasthemainclinicalmanifestations,intestinalsymptomsnotobvious23

Clinicalmanifestationstoxictype:shocktypepaleface,skintinea,limbextremitiespurplebloodpressureearlycanbenormal,butalsocanreduceandevencannotbedetectiveurineoutput:oliguriaoranuriaconsciousness:disturbanceofconsciousnessindifferentlevel24

Clinicalmanifestationstoxictype:cerebraltyperespiratoryfailuretype:highfatalityratecerebralvasospasm:cerebralischemia,hypoxia,cerebraledemaandintracranialpressure,seriouscerebralherniacanoccurtoxictype:mixedtypetheperformanceofboththeshocktpyeandcerebraltpyethemostdangerousandthefatalityrateisveryhigh25

Clinicalmanifestationschronicbacillarydysentery:thecourseofthediseasemorethan2monthsreasons:antimicrobialtreatmentisnotcompletelyduringtheacutephasedrug-resistantstrainsinfectionpatientswithmalnutrition,originallowimmunefunctiontpyies:

Acuteattacktype:sameascommonacutedysentery

Chronicdelayedtype:long-timeandrepeateddiarrhea

Chronicobscuretype:acutehistoryin1year,nosymptoms,stoolcultureorsigmoidscopyPos.

26

ClinicalmanifestationsChronicbacillarydysentery:

Chronicdelayedtypelong-termrecurrentabdominalpain,diarrhea,oftenmucusandpurulentbloodstoolsymptomssuchasfatigue,malnutritionandanemiadiarrheaalternatingwithconstipation27

ClinicalmanifestationsChronicbacillarydysentery:Acuteattacktypehasahistoryofchronicbacillarydysenteryeatingcoldfood,tired,orcatchcoldcauseacuteepisodesabdominalpain,diarrheaandpurulentbloodfeverandsystemicsymptomisnotobvious28

Clinicalmanifestationschronicbacillarydysentery:Chronicobscuretypehasahistoryofacutebacillarydysenteryinlastyearnoobviousabdominalpain,diarrheastoolculturecanhavedysenterybacillusintestinalmucosalinflammationandevenulcerlesionscanbefoundbysigmoidoscopy29LaboratoryFindingsBloodRoutineExamination:totalWBC:10~20%×109/Lneutrophils:shifttotheleftStoolexamination:directmicroscopicexam.:WBC,RBC,puscellsormacrophage30313233The"goldstandard”-stoolcultureacutephaseofdiseasefreshlypassedstoolblood-tingedplugsofmucuspromptinoculationRectalswabs

AccreditedTechnicians

LaboratoryFindings34LaboratoryFindings35Othermethods:PCRSigmoidscopyX-ray:irrigo-radioscopyLaboratoryFindings363738Complicationbacillusdysenteriaesepsishemolyticuremicsyndrome(HUS)reactivearthritis(Reiter'ssyndrome)39DIAGNOSIS1.epidemiologicdataandhistory2.clinicalfeatures:symtomsandsigns3.Labfindings:

40DifferentialdiagnosisAcutedysenteryEnteritiscausedbyE.Coli,salmonella,viraldiarrheaIntussusception:jelly-likestools,abdominalmassandabsenceoffeverAmebicdysentery41ToxicsymptomseveremilddiarrheaseveremildtenesmusnotednoBacillaryAmebicabdominaltendernessleftright42stoolblood,mucus,andpusjam-like,reddishmicroscopyLeukocytes,erythrocytesAmebictrophozoiteendoscopyhemorrhagic,withmucousdischargeandfocalulcerationsflask-shapedulcer,43Toxicdysentery(brainform)JapanessBencephalitisa.slowlyb.stoolc.CFS-IgMd.shockrarelyDifferentialdiagnosis44ChronicdysenteryRectal&coloniccarcinoma:nocureforlong-term,dropofweightofbodynon-specificulcercolitis:no